Avalanche Forecast
Issued: Dec 12th, 2012 9:14AM
The alpine rating is Storm Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
A series of frontal systems will affect the area for the next few days.Thursday: Strong to gale NW winds. Alpine temp -6. Moderate snow. Friday: Moderate W winds. Alpine temp -7. Light snow.Saturday: Light winds. Alpine temp -10. Moderate to heavy snow.
Avalanche Summary
We have no reports of avalanches during Monday or Tuesday, but that may be due to a lack of observations more than a lack of avalanches. In the NW Coastal region, the basal weakness was triggered by heavy loads (cornice fall, surface avalanches stepping down and explosives) to produce very large avalanches. Strong W-NW winds triggered a natural avalanche cycle inland on Sunday, with several slabs to size 2 failing behind cross-loaded ribs and gullies. A size 2.5 slab from the headwall above the Hankin-Evelyn area is suspected to have failed on the Nov crust/facet layer.
Snowpack Summary
New and buried wind slabs exist on a variety of slopes due to strong, variable winds over the last week. In the alpine, some areas are scoured to rock, while you may find 2 m + in windloaded areas. A rain crust formed a couple of days ago on low elevation slopes. Surface hoar is buried in the upper pack at treeline in isolated sheltered areas. We havenât had any recent reports of reactivity on this layer. A November crust/facet layer near the base of the snowpack has the potential for deep releases, particularly from a thin-spot trigger point or with a heavy trigger like cornice fall or a surface avalanche stepping down. Expect new storm slabs and wind slabs to develop during the remainder of the week as a series of fronts hits the region.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 13th, 2012 2:00PM